Pianoforte-action



UNITED STATES PATENT OFFICE.

ALEXANDER HARL, OF LLOYDSV ILLE, OHIO.

PIANOFORTE-ACTION.

Specification of Letters Patent No. 10,776, dated April 11, 1854.

To all 107mm 2f may concern Be it known that I, ALExANDER'I-IALL, of Lloydsville, in the county of Belmont and State of Ohio, have yinvented certain Improvements in Octave-Pianos, and that the following is a full, clear, and exact description of the principle or character which distinguishes them from all other things before known and of the usual manner of making, modifying, and using the same.

In the performances upon the pianoforte playing in octaves above the normal notes is not very often introduced on account of the diiiiculty of execution though the effect is always brilliant and delightful. In most pieces the bass so well balances the tenor and treble on one side -that the ear has no desire for octaves below the normal notes compo-sing the air but the ear always craves the octave above to fill up the full measure and power of each note. Attempts have been made to introduce octaves below the normal notes by the introduction of a few extra strings and an extra bridge exterior to the usual bridge. Besides t-he fact that there exists little or no necessity for the introduction of such notes, it is not `possible to introduce them successfully without elongating, the whole instrument to a considerable extent for the following reason. It would not answer to make all the strings in a piano or any other instrument of the same size and length and regulate the notes merely by the tension of the strings. A certain relation between the size, length and tension of each string must be observed in order to get full and clear tones, hence the impracticability of carrying out the introduction of the octave below notes even if it were very desirable, for the great increase in the size of the instrument would be a serious objection the lpiano forte being already. very cumbrous. By my plan however of introducing oct-aves above no extra room is taken up, the bridges for the octave strings being placed within the usual bridges of the piano on or over the resounding board. There is no complication of the action, a fatal objection to some of the attempts that have been made to introduce the upper octaves, and by a device of great simplicity I am enabled to play the octaves or not at pleasure.

The nature of my invention consists in a peculiar arrangement of the strings, bridges, and action of the piano forte by which I am enabled to introduce the upper octaves in addition to the normal notes, while playing upon the instrument., I have also invented a new hammer head by which I am enabled to strike with the proper effect, two strings of different degrees of tension. I am aware that various efforts have been made to introduce the uper octaves while playing and that every attempt to do this by mechanism has failed while the introduction of the upper octaves by the touch of the performer' though brilliant in effect is always at the expense of melody and execution. In order to retain the free use of all the fingers, some distinguished artists have resorted to what have been called artistic fingers, they being artificial lingers attached to the wrist or the hand for the purpose of touching the octaves.

Figure l, is a top view of the open instrument and Fig. 2 is a top view with the strings and sounding board removed.

My mode of introducing the upper octaves is as follows: In addition to the usual bridges a a for the normal strings of the piano I employ the extra bridges (l, CZ, so as to give to the octave strings their appropriate length. The octave strings are denoted by letter (0) and the normal strings by lette-r The bridges (d, cZ,) may be separate or all united so as to form one bridge, and are attached to the sounding board. They may however be detached from and a little distance above the sounding board. The bridge (CZ) having a curvature nearly like the common bridge (a) is employed for a special reason, to wit. The bridge (a) would not answer as the bridge for the octave strings for it has been found that the best tones are attained by causing the hammers in piano fortes to strike some harmonic node of the string and the distance of one eighth from the bridge is that adopted. Now as I am to employ but one hammer head for each string and its accompanying octave, the nodes of the normal and octave strings must both come together directly over the hammer head. The vdrawing is not exact to the scale of proportion but their approximation together with this statement and description will suflice.

In order to suit the character of the ham-` mer heads to the double function of playing high and low tones with the same head, I make that part of the head (6') which strikes the octave, of a harder texture than the part (.79) which strikes the normal strings, by which I am enabled to bring out full t-ones on each string. Vhere dampers are used in piano fortes to stop the action upon one set of strings as for instance by the common harp pedal, the mufHing 0f one string diminishes the volume of sound from the other, whereas if the action could be shifted so as to strike only one string the other being left free to vibrate, would contribute to the volume of sound by resonance or sympathy. As in my octave piano I prefer to use but one normal string I preserve to the octave string full freedom to vibrate by a peculiar mode of shifting the action, when I wish to play upon the normal strings without the octaves.

It is necessary in piano fortes that the hammers should so strike the strings that the longest diameter of the face of the hammer should be parallel with the line of the strings. This has hitherto presented an obstacle to the introduction of shifting action in square pianos, where the hammer heads are twisted round for the upper notes, so as to be in seven octave pianos entirely at right angles to the hammer heads for the low notes. But from the relative posi.-

tions of the bridges and strings for the normal and upper octave notes my shifting action becames perfectly adapted to the purpose and the hammer heads though mov ing in an arc yet fall in the shifting operation, under the nodal points of both strings. This result it will be seen would be impracticable in. the case of two normal unison strings as in the common piano forte.

This device is as before mentioned one of great simplicity and consists in pivoting the key board (a) at the point (aa) or some point near this end so that when the free end is pushed inward the proper distance all the hammer heads move round in an arc as shown by the dotted red lines and fall under the nodal points of both strings. Before the key board is pushed inward the hammer heads strike only the normal strings as shown in the drawings.

My piano I denominate the Celestial piano.

vWhat I Claim as my invention and desire to secure by Letters Patent isl. The arrangement of the bridges of the upper octave strings in combination with the shifting action so that the nodal points of these strings may coincide with those of the normal strings, in the manner set forth.

2. I claim the mode of shifting the action by pivoting the key board in combination with the employment of upper octave strings in the manner set forth.

3. I claim making the hammer heads of hard and soft material for the purpose of playing with effect upon the upper octave and normal string with the same hammer head.

ALEX. HALL.

lVitnesses:

CHAs. G. PAGE, ToLMIE CAMPBELL. 

